for Thunder of the Sierra by Kathy Balmes and Vicki Catapano
When recently orphaned Mateo loses his beloved palomino to the notorious bandit Joaquin Murieta, he has only one thought -- he must get her back. But in a dangerous Gold Rush era California, that is no easy task. Swearing to track down his horse, Mateo becomes an arriero -- leading pack mules through gold rush camps, lightning storms in the Sierra, and risky encounters with crazed miners. But when he learns that his father's old rancho may be in danger from Yankee squatters, aided by the new American government, Mateo begins to realize that more is at stake than the fate of his horse.